Which one is the toilet vent?

[cysperus]

There's a lot of pipes sticking out from my Roof. Some have covers and some do not. How do you know which one is a plumbing vent?

 

[Cass]

It will be white plastic, cast iron or copper depending on when your house was built and it won't have a cover. It will also be 3-4" ID and will look like 4-5" from the ground looking up.

 

[Sponsor]

 

[hj]

vent

Then I guess all the black pipes sticking out of houses around here are not vents. And the number of newer ones, (i.e., those within the last 10-15 years), with a 3" or 4' vent out the roof might not add up to a handful.

 

[Cass]

Oh yeah ABS. There is none around here, I only see it rarely and then never out the roof, always just 1.5". The only other oddity I have seen once is a house built with Sch. 80.

 

[Abikerboy]

There's a lot of pipes sticking out from my Roof. Some have covers and some do not. How do you know which one is a plumbing vent?

Turn on water in sink, tub/shower, and/or have someone flush toilet while listening at top of each pipe. Went through this at my mom's house while trying to find bathroom vent, and even with vent pipe plugged solid with debris, I could still hear the sound of draining water at top of vent pipe when toilet was flushed. Also, turn on exhaust fans. That way you can eliminate these pipes first thing.
Rob